Importance of $\Delta V_{{\text {DIBLSS}}}/({I}_{{\text {on}}} /{I}_{{\text {off}}})$ in Evaluating the Performance of n-Channel Bulk FinFET Devices

Abstract

This paper aims to investigate the recently proposed figure of merit, ΔVDIBLSS/(Ion/Ioff), in detail. Experimental results show that ΔVDIBLSS/(Ion/Ioff) represents the index of device immunity to short-channel effects in bulk FinFETs. The value of its numerator, ΔVDIBLSS, accounts for the drain-induced barrier lowering and subthreshold swing. The value of its denominator, Ion/Ioff, accounts for the transistor performance in transitioning between on and off states. Small ΔVDIBLSS and large Ion/Ioff are desirable, representing the improved gate control over the channel potential. We found that both ΔVDIBL and ΔVSS values are more correlated with the drain off-state current, Ioff, than they are with the drain on-state current, Ion. A high-performance FinFET device exhibits ΔVDIBLSS of about 100 mV and Ion/Ioff of about 1 × 106. Thus, ΔVDIBLSS/(Ion/Ioff) in a high-performance FinFET device is expected to be around 1×10-4 mV. Using this figure of merit, along with the verification using conventional parameters such as ΔVDIBLSS and Ion/Ioff, the proposed device shows better electrical characteristics than that in our previous work due to the optimized process conditions implemented.

Keywords

• ΔVDIBLSS/(Ion/Ioff)
• bulk FinFETs
• drain–induced barrier lowering
• short–channel effects
• subthreshold swing